Skip to main content

PID Gains

The PID gains subprotocols allow the GCS to read and update the PID gains for the various controllers used by the UAV.

PID Gains Read​

The PID gains read subprotocol allows the GCS to read the PID gains used by the UAV in one of its controllers, either initiated by the Operator or when a connection is established.

Messages​

  1. PID_GAINS_READ_REQUEST
  2. PID_GAINS

Sequence​

sequenceDiagram
    participant GCS
    participant UAV

    loop n
        GCS->>UAV: PID_GAINS_READ_REQUEST
        GCS->>GCS: Start timeout
        alt success
            UAV-->>GCS: PID_GAINS
        else failure
            GCS->>GCS: Timeout expires
        end
    end
  1. If the GCS wants to read the stored PID gains of a specific controller from the UAV (including when a connection is established), it sends a PID_GAINS_READ_REQUEST message to the UAV.
  2. The GCS starts a timeout of a fixed duration.
  3. If the UAV responds with a PID_GAINS message before the timeout expires, the operation is considered a successful.
  4. If the timeout expires before the UAV can respond, the GCS retries the operation upto n times before the operation is considered a failure, the error is reported and the UAV continues operations.

PID Gains Write​

The PID gains write subprotocol allows the GCS to update the PID gains used by the UAV in one of its controllers.

Messages​

  1. PID_GAINS_WRITE_REQUEST
  2. PID_GAINS_WRITE_REQUEST_ACK

Sequence​

sequenceDiagram
    participant GCS
    participant UAV

    loop n
        GCS->>UAV: PID_GAINS_WRITE_REQUEST
        GCS->>GCS: Start timeout
        alt success

            loop n
                UAV-->>GCS: PID_GAINS_READ_REQUEST
                UAV->>UAV: Start timeout

                alt success

                    loop n
                        GCS->>UAV: PID_GAINS
                        GCS->>GCS: Start timeout

                        alt success
                            UAV-->>GCS: PID_GAINS_ACK
                        else cancelled
                            UAV-->GCS: PID_GAINS_NACK
                        else failure
                            GCS->>GCS: Timeout expired
                        end
                    end
                else failure
                end
            end

        else cancelled
            UAV->>GCS: PID_GAINS_WRITE_REQUEST_NACK

        else failure
            GCS->>GCS: Timeout expires
        end
    end
  1. If the GCS wants to update the stored PID gains of a specific controller from the UAV, it sends a PID_GAINS_WRITE_REQUEST message to the UAV (includes the new PID gains).
  2. The GCS starts a timeout of a fixed duration.
  3. If the UAV responds with a PID_GAINS_WRITE_REQUEST_ACK message before the timeout expires, the operation is considered successful.
  4. If the timeout expires before the UAV can send a response, the GCS retries the operation upto n times before the operation is considered a failure, the error is reported and the UAV continues operations.